Gas mixer



Aug.'30, 1938. ADAMS 2,128,519

GAS MIXER Filed Aug. 16, 1935 Geo/7e IQ. Adamf Patented Aug. 30, 1938 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to new and useful improvements in gas mixers.

One object of the invention is to provide an improved mixer which is particularly adapted for 5 use with internal combustion engines and which will effectively and automatically admix air with the gaseous fuel according to the load imposed on the engine.

An important object of the invention is to pro- 10 vide an improved gas mixer which is arranged to be communicably connected in the usual air horn, or inlet, of the gasoline carburetor of an internal combustion engine and which is so constructed as not to interfere with the normal operation of 5 said gasoline carburetor, whereby the internal combustion engine may be operated either on liquid fuel, such as gasoline, or gaseous fuel, such as natural gas; the structure of the mixer being i such that the change from one fuel to the other :10 may be accomplished without stopping the engine. Another object of the invention is to provide an improved gas mixer including a valve for controlling the admittance of the gaseous fuel to the air stream, said valve being controlled by the suc- 5 tion of the engine, and means associated with said valve for metering the flow of gaseous fuel past the valve, said metering means being so arranged that the supply of fuel is increased as the suction of the engine increases due to an in- 30 creased speed of or an increased load on said engine, whereby the mixture is enriched under such conditions.

Still another object of the invention is to provide an improved gas mixer for internal combus- 35 tion engines including a spring-pressed valve, actuated by the engine suction, for controlling the admittance of gaseous fuel to the air stream in the mixer, the spring for resisting the opening of the valve being constructed in a spiral, whereby 4 when the valve is first opened, resistance is slight While as the valve opens further the resistance is increased proportionately, thereby making the valve sensitive at starting and under light loads, and steady under heavier loads or running condi- 45 tions.

A still further object of the invention is to provide an improved gas mixer for internal combustion engines having a Valve for controlling the inlet of gaseous fuel, said valve being actuated by 50 the engine suction, with means for resisting the opening of said valve whereby a certain suction is necessary to open the valve, said resisting means being adjustable so that the resistance to the opening of said valve may be increased or 55 decreased, which will make the mixer adaptable for use with engines of various sizes since each engine develops a different suction which acts upon said valve.

A construction designed to carry out the invention will be hereinafter described, together with 5 other features of the invention.

The invention will be more readily understood from a reading of the following specification and by reference to the accompanying drawing, in which an example of the invention is shown, and wherein:

Figure 1 is a side elevation of an engine having a gas mixer, constructed in accordance with the invention, mounted in the air hornof the engine carburetor, 16

Figure 2 is a side elevation of the gas mixer,

Figure 3 is a transverse vertical, sectional view of the same,

Figure 4 is a horizontal, cross-sectional view,

taken on the line 4-4 of Figure 3, and 20 Figure 5 is a horizontal, cross-sectional View, taken on the linev 55 of Figure 3. i

In the drawing the numeral l0 designates. a cylindrical, elongated body or casing which is con-, structed of metal, or other suitable material. The lower end of the body is reduced at H, and this lower reduced end is provided with an enlarged circular air inlet l2 which, as clearly shown in Figure 5, is located in the side wall of the body. The upper end of the body is provided with an outlet opening l3 which is preferably located diametrically opposite the air inlet l2 at the lower end of said body. An outwardly extending collar l4 surrounds. the opening I3 and is preferably made integral with the body. The extreme outer end of said collar is reduced whereby an external annular shoulder I5 is formed substantially midway of said collar.

As clearly shown in Figure l the collar 14 is of such size as to snugly fit within the air horn, or air inlet iii, of the usual gasoline carburetor ll of an internal combustion engine. When so inserted, it will be obvious that the air entering the body I 0 through the air inlet l2 will pass through said body and outwardly throughtheopem'ng I3 Q and into the air horn iii of the gasoline carburetor in the usual manner. Therefore, it will be seen that the mounting of the body ill on the carburetor I! will not interfere in any way with the normal operation of said carburetor.

A gas inlet port I8 is formed in the wall of the body It! at approximately mid-height thereof. This port extends radially through the wall of the body and has a suitable gas supply pipe l9 connected therein, whereby gaseous fuel may be introduced through the port l8 into the body. A cylindrical conductor 20 is disposed axially within the casing and has its lower end bent at right angles to itself, whereby said lower end may connect with the port I8. The conductor 20 has its upper end terminating at some distance below the outlet opening I3 in the side wall of the body I0. With this arrangement it will be seen that the gaseous fuel entering through the supply pipe I9 will pass through the port I8 and then through the. conductor 20 which will direct the fuel upwardly into the body It above the upper end of said conductor.

The upper end of the conductor is machined to form an annular valve seat 2| which is preferably disposed at substantially a 45 degree angle.

A vertically sliding valve 22 is provided with a complementary bevel 23 which is arranged to engage the beveled seat 2|. The upper end of the valve is formed with an annular flange 2 l and by observing Figure 3, it will be seen that when the bevel 23 is engaging the seat 2| said flange overhangs the conductor. The diameter of the flange 24 is slightly smaller than the interior diameter of the body Ill whereby when the valve is closing the upper end of said conductor 20, there is a space formed between the outer edge of said flange and the interior wall of the body. Thus air which enters the inlet I2 at the lower end of the body may pass upwardly through the body and pass around the annular flange 24 upwardly into the body.

Depending from the flange 24 and below the annular bevel 23 of the valve is a tapered head 25. This head, as clearly shown in Figure 3 is reduced toward its lower end and an axial elongated stem 26 depends from the bottom of said head. The stem extends downwardly through a guide sleeve 21 which is preferably formed integral with the underside of the conductor 20. It is obvious that the stem will guide the valve in its vertical movement. It is noted that the valve stem 26 and its guide 21 are located below the gas port I8 and thus, the gas which is entering the conductor 20 through the supply pipe I9 will not contact the guide, whereby all danger of corroding due to such contact is eliminated. Therefore the stem will not have a tendency to stick or jam within the guide which makes for positive operation of the vertically sliding valve 22.

It will be obvious that when the body I I] is connected with the usual gasoline carburetor that the valve 22 is exposed to the suction of the engine. Thus this suction will raise the valve to permit the entrance of gas into the body. At the same time the suction will draw air into the body through the air inlet I2 and it is obvious that when the valve 22 is open gas is introduced into the air stream which is flowing upwardly through the body, whereby a combustible mixture is produced. This mixture is then carried to the cylinders of the engine in the usual way. It is noted that since the upper end of the conductor is located axially within the body the air will flow upwardly through the body around the conductor in an annular" stream. When the valve is open the gas will be introduced into this annular air stream whereby proper mixing is assured.

For resisting the opening of the gas valve 22, so that a predetermined suction is necessary to raise said valve to permit the admittance of gaseous fuel, a coil spring 28 is provided. The spring is coiled in a spiral with the larger spirals at the base of the spring and resting upon the upper end of the valve 22. The upper reduced .through the top 30 of the body.

operating conditions.

end of the spring 28 is secured to the lower end of an adjusting screw 29 which is threaded It is noted that this top 30 is preferably threaded into the upper end of the body whereby ready access to the interior of said body is had. If desired, a suitable lock nut 3| may be threaded on the adjusting screw 29.

It will be obvious that by adjusting the screw 29, the tension on the spiral spring 28 may be readily varied. Thus the gas mixture herein shown and described may be adapted to engines of various sizes because the larger the engine is, the greater suction its piston will create under By tightening down on the adjusting screws 29 the tension of the spiral spring 28 against the valve 22 will be increased, whereby a greater suction is necessary to raise the valve. Similarly, if the screw 29 is raised then the spring tension against the valve 22 is lessened, so that less suction is necessary to lift the valve from its seat. It is further noted that by making the spring spiral as shown, that the resistance against the valve opening is less at the start of the raising of said valve due tothe larger coils of the spring being at the bottom. In other words less suction is required to lift the valve its first eighth of an inch, thereby making the valve very sensitive when the engine is first started or when said engine is operating under a light load. Of course, as the valve is raised the spring 28 is compressed and due to the coils of the spring reducing toward the upper end of said spring, it will be obvious that the tension will increase as the valve moves upwardly. This causes a greater resistance to the valves movement after the engine has been started or under heavy load, which makes for a steadier operation of the valve under such condition, thereby eliminating fluctuating of the valve to admit the gas into the air stream in an even quantity.

In operation, the collar I of the gas mixer body In is inserted into the air horn I6 of the usual gasoline carburetor of the internal combustion engine A. If it is desired to operate the internal combustion engine on gasoline, then it is only necessary to close a control valve B which is mounted in the gas supply line I9. This prevents any gas from entering the gas mixer body ID. The engine is then operated in the normal way the gasoline flowing to the carburetor being controlled by the usual throttle, while the air is introduced into the carburetor I! through the air inlet I2 in the body ID. This air flows through the body and through the opening I3 in the upper end thereof, and then to the air horn of the carburetor H, where it will admix in the usual way with the gasoline being supplied to said carburetor. Thus, it will be seen that the connection of the gas mixer body II] to the usual carburetor does not interfere in any way with the operation of said carburetor. So long as the gaseous fuel which enters the body In through the inlet port I8 from the supply pipe I9 is cut off, then the gasoline carburetor will operate in the usual way without interference from the gas mixer.

When it is desired to operate the engine A on gaseous fuel, such as natural gas then it is only necessary to open the control valve B which will permit the gaseous fuel to enter the conductor within the body Ill. At the same time the valve of the carburetor which controls the admittance of liquid fuel, such as gasoline to the carburetor I1 is closed. This closing of the liquid supply controlling valve cuts out the carburetor l1 and continued operation of the motor will then cause the valve 22 within the body IU of the gas mixer to raise and admit the gaseous fuel into the air stream within the body, so that the subsequent mixture will pass through the carburetor l1 and into the motor. It is noted that the change from the gasoline carburetor to the gaseous fuel mixer may be accomplished while the engine is operating. In other words, it is not necessary to stop the operation of the engine in order to make the change. It is noted that the air for both the gas mixer and the carburetor is supplied through the air inlet |2 of the body I0 of said gas mixer. It is further noted that when the gas mixer is employed, the mixture of the gaseous fuel with the air is passed through the carburetor I! which is inoperative at this time and then to the motor. In this way the carburetor I1 and the gas mixer body ID are secured to each other but when one is inoperative, it does not interfere with the operation of the other. This permits the change from gasoline to gaseous fuel in operating the engine to be made during the operation of said engine without the necessity of stopping the same.

When the carburetor H has been out out and becomes inoperative it will be obvious that the suction of the engine will draw the air through the air inlet I2 at the lower end of the body l0 and will cause the same to flow upwardly through the body around the axially disposed conductor 20. It is noted at this point that the air inlet opening |2 may be increased or decreased as desired through the medium of a collar 32 which surrounds the lower reduced end ll of the body. This collar is provided with a cylindrical opening 33 which has the same diameter as the air inlet 2 in the wall of the body. By observing Figure 5, it will be seen that by rotating the collar on the lower end of the body the opening 33 in said collar may be moved with relation to the air inlet I2 whereby the inlet opening through which the air may enter the body I0 is either enlarged or decreased. The collar 32 may be supported in any suitable way on the lower end of the body but it is shown as resting on an annular external shoulder 34 formed at the lowerend of said body below the'air inlet |2.

At the same time that the suction of the engine draws the air through the inlet opening l2 it will act against the valve 22 to raise the same from the annular valve seat 2|. There is little resistance to the initial movement of the valve 22 besaid valve sensitive and easily operated when the engine is first started or is operating under a very light load. It is obvious that as soon as the valve raises from the annular seat 2| the gaseous fuel being supplied through the pipe |9 passes upwardly through the conductor and is admitted into the upwardly passing air stream within the body I. This gas will, of course, immediately admix with the air stream and will be carried upwardly therewith and drawn through the outlet opening |3 in the upper end of the body, then through the carburetor I1 and to the engine cylinder, in the usual way. I

As the speed of the engine increases it is, of course, necessary to supply a greater amount of gas in proportion to the air, because more air will be drawn in due to the greater suction crecarbureting system of said engine.

ated by theincreased speed of the engine. To provide for a metering of the gas so that the supply of gas is increased proportionately as the suction of the engine increases, the tapered head 25 which depends from the annular bevel 23 of the valve is provided. It is noted that the diameter of this head at the point where it merges into the bevel seat 23 is substantially the same as the diameter of the axially disposed conductor 20. However, since the head is reduced toward its lower. end it will be seen that the diameter of said head at the lower end is comparatively smaller than the interior diameter of the conductor 20. Thus, as the valve 22 1s lifted from its seat due to an increased suction of the engine caused by an increased speed of said engine or an increased load imposed on said engine, it will be obvious that the space between the outer surface of the tapered head 25 and the interior wall of the conductor 20 is gradually increased. As the valve moves upwardly a greater amount of gas is permitted to flow past the valve seat 2| and into the air stream passing upwardly through the body In thereby increasing the gas supply in proportion to the increased amount of air being drawn through the air inlet I2, whereby a proper mixture is maintained at all times and under all conditions.

It is noted that when the engine is accelerated or an increased load is imposed thereon, the suction of the engine automatically increases to draw in a greater amount of air through the inlet 12. As this occurs the tapered head 25 permits a greater supply of gas to be admitted to this increased amount of air to maintain the proper mixture under acceleration or under heavy load. The metering ofthe gas to increase the volume of the gas entering the air stream is automatically accomplished because the further the valve raises due to the increased suction the greater the volume of gas which is permitted to flow past the valve seat 2|. With the above arrangement the operation of the mixer is entirely automatic and is controlled by the suction of the engine. The

spiral spring 28 not only makes for a more eflil "may be adjusted so as to be applied to any engine and the valve 22 will operate as emciently in an engine of one size as it will in an engine of another size. The fact that the mixer may be attached in the air horn l6 of the usual carburetor is an important feature of the invention. I

It will be seen that the mixer may be applied to an engine without changing the structure or It will not interfere with operation of the usual carburetor "and therefore when an engine has the mixer, as

shown and described, applied thereto, said engine may be operated either on a liquid fuel such as gasoline through the use of its ordinary carburetor. Also if desired, it may at any time be changed over to be operated on a gaseous fuel, such as natural gas, the change being accomplished without stopping said engine. The gas mixer will not interfere in any way with the operation of the carburetor, and when the liquid supply controlling valve of said carburetor is closed the carburetor will not interfere with the operation of the gas mixerv Thus,.it will be seen that an engine may be readily:convertedfirom gasoline operation to. natural gas operation.

The gas mixer is automaticallyoperatedby the suction .of the engine and has only-thesingle moving part whichis the valve, 22. The body, in may be cast in'xa single-piece-whereby manufacturing costs are reduced to a minimum. The only machining necessary is in forming the annular valve seat H at the upper end of the conductor 29. It will be obvious that the gas mixer may be readily attachedto or detached from the air horn E6 of the usual carburetor, and also the mixer may be readily dismantled for cleaning, or other purposes at any time. ,The only adjustment to be made is thatof the tension on the spring 28 and ionce this has been done, the mixer needs no further attention as there are no manual adjustments or controls which may become worn and cause trouble.

What I claim and desire to secure by Letters Patent is:

l. A suction-controlled gas and air mixingdevice including, an elongate vertical hollow cylindrical body provided with an air inlet at its lower end portion and provided with a rotatable sleeve having an opening to be brought into different degrees of registration with the air inlet opening of the body to vary the capacity of air intake, and an outlet at its upper end having provision for communicable connection in a suction conduit, a cylindrical gas Conductor located axially in said body between the lower air inlet and the upper outlet and with an annular passageway between said conductor and the surrounding wall portion of the body, said conductor being open at its top but otherwise closed to the interior of said body, a suction-controlled valve element normally supported upon and closing the open top of said conductor, said valve element and conductor having cooperative annular seat portions, the valve element having a head on its under side tapering downwardly from its base contiguously within the annular seat portion of the element and disposed axially in the conductor, said element also provided with annular flange overhanging the space between the conductor and the surrounding wall of the body and being of a peripheral diameter slightly less than the interior diameter of the body, and spring means for yieldably holding the valve element in its seated relation to said conductor and proportionately controlling the lifting of the element as suction is created and varies within the body chamber above the element. 7

2. The herein described suction-controlled gas and air mixing attachment including, a vertical hollow cylindrical body provided with an air inlet at its lower endportion and provided with a rotatable sleeve having an opening to be brought into different degrees of registration with the air inlet opening of the body to vary the capacity of air intake, and a lateral outlet at its upper end having provision for communicable connec- :tioninasuction conduit,s'a cylindrical gas con- .cluctor located axially in said body between the lower air inlet and theupper outlet, said conductor supported at its lower end-upon the body wall by a lateral-tubular extension connected with a gassupply pipe and being open at its upper end,.but otherwise closed to the interior of the .interior of the body, a valve element resting normallyupon and closing, the Open upper end of said conductor, said valve element having an annular flange overhanging the space between the conductor and the surrounding wall portion of thebody and being of, a peripheral diameter slightly less than the interior diameter of the body,.the engaging portions of the valve element and the conductor being formed with cooperative beveled annular seats and the valve element provided with a head tapering downwardly from its under side contiguous to the seat portions and axially into said conductor, said head having an axial stem extending downwardly in a guide sleeve provided therefor at the lower end of said conductor, and a spring disposed above and pressing upon said valve element toyieldably hold it in its normally closed relation tothe conductor and proportionately resisting the lifting of the valve element according to variation in suction created within the body chamber above the element.

3. The herein described gas and air mixer including, an elongated .verticalhollow cylindrical body having a lateral air inlet opening in its lower end portion and provided with a rotatable sleeve having an opening to be brought into difierent degrees of registration with the air inlet opening ,of the body to vary the capacity of air intake, said body having a removable upper end closure and a lateral outlet opening adjacent the end closure with provision for communicable connection in a suction conduit, a cylindrical gas conductor supported axially in said body below the outlet openingjthereof and above the air inlet opening in annularly spaced relation to the surrounding body wall, said conductor being open at its top but otherwise closed to the interior of the body, a valve element comprising a flat circular plate portion of a peripheral diameter slightly less than the interior diameter of the body and formed with a beveled annular seat on its under side to engage a counterpart seat provided therefor at the upper end of said conductor,

said valve element provided on its under side with a downwardly tapering head merging at its .base with the annular seat portion and extending axially into said conductor, an axial stem extending downwardly from said head of the valve element and fitted slidably in a guide sleeve ,pro-

vided therefor on said conductor, a tapered coiled spring disposed with its larger :end downward and engaging the upper side of said valve element, .and a longitudinal adjusting screw mounted ax- 

